A motion picture museum at LACMA will only add to the disparate shape of the campus, which is ultimately a smaller snapshot of Southern California itself.

When Michael Govan was named director of the Los Angeles County Museum of Art in 2006, there was reason to hope that LACMA's campus — in its jumbled, sprawling form something of a microcosm of Southern California urbanism — might finally gain some architectural coherence.

Govan arrived at the museum with an impressive architectural track record, having overseen the construction of a terrific satellite campus for the Dia Art Foundation, designed by artist Robert Irwin and the architecture firm Open Office, in Beacon, N.Y. Before that he worked alongside Thomas Krens as the Guggenheim director plotted a program of global expansion starring the world's leading architects.

But the news last week that Govan had decided to lease the LACMA West building to the Academy of Motion Picture Arts and Sciences, abandoning a plan to renovate it for its own use, caps a series of decisions that have hardly unified the museum's campus. If anything, in five years as director, Govan has seemed to embrace the contradictory qualities of the museum's architecture — or at least concede, as other LACMA directors have done publicly or privately before him, that it may be immune to a streamlining impulse.

And in the end, maybe that's a sign that he has come to understand the peculiar role LACMA has long played in the city, and the way it seems to attract and then foreclose visionary architectural plans.

At least from a bottom-line perspective, it's easy to see the thinking behind the decision by Govan and his board to hand over the old May Co. building at Wilshire Boulevard and Fairfax Avenue, which it acquired in 1994 and renamed LACMA West, to the academy for its long-planned movie museum. In a single stroke, Govan has freed LACMA from the cost of renovating the building for its own use and guaranteed a steady stream of lease revenue and new visitors.

When you consider that a Metro subway line will be coming to Wilshire and Fairfax by the end of the decade, the plan looks even smarter. With a major transit stop and a movie museum at its front door, it's not hard to imagine the museum's annual attendance leaping well past the 2010 figure of just more than 900,000.

The architectural implications of the decision are more complicated. LACMA had been working with the Culver City firm SPF Architects to renovate the May Co. building, adding galleries and offices, and there were plans for a pair of installations by the artist James Turrell on its rooftop. The academy, for its part, had hired the French architect Christian de Portzamparc to work on preliminary designs for a planned museum in Hollywood.

At this point, it's unclear who will design the new movie museum inside the May Co. building and how it will look — to say nothing of its relationship with the rest of LACMA. What is clear is that the museum campus is now settling into three distinct — and architecturally very different — sections.

On the western edge will be the film museum, with 300,000 square feet of galleries inside the 1939 May Co. building, a landmark of Streamline Moderne architecture by Albert C. Martin. LACMA has ceded control of these interiors to the academy, which means the museum will probably look something like recent projects by David Rockwell, who designed the Kodak Theatre, where the Oscars are handed out each year, and the last two stage sets for the ceremony.

In the center is the main museum campus — itself an architectural hodgepodge, mixing a pair of new gallery buildings by Renzo Piano with the original 1965 William Pereira campus and a 1986 addition by Hardy Holzman Pfeiffer. This area — the only one in which Govan has so far had a direct impact on the shape of the campus — will offer a transition between the poles of mass appeal and cutting-edge architecture.

It already mixes two gallery buildings and an entry pavilion by Piano with a restaurant and cafe and giant installations, nearly all of them big enough to have architectural scale, by artists including Chris Burden and Tony Smith. Next month an even bigger piece — a 340-ton granite boulder suspended over a sunken walkway — will arrive at LACMA courtesy of artist Michael Heizer. And Govan hasn't given up on plans to install a huge hanging train by Jeff Koons.

To the east, finally, is a relatively open patch of land, the location of Bruce Goff's Japanese Pavilion and not much else. This is the part of the campus where Govan has been making preliminary plans with the Swiss architect Peter Zumthor, though those designs are on hold as the economy continues to stumble.

These three sections promise to trace a fascinating path from populist to rarefied architecture. While the movie museum will presumably play to a broad public, it's hard to think of an architect less open to pop-culture influence than the exacting, slow-working, hugely talented Zumthor.